Convoluted chocolate sheets are known in the art, and typically consist of a thin sheet of chocolate which is irregularly folded onto itself to create a bulk chocolate layer having a multitude of relatively large, irregular, air pockets therein. For example, the Applicant has produced a product under the trade name CADBURY FLAKE® since 1920, consisting of a bar of convoluted chocolate sheet. The combination of the relatively thin sheet of chocolate with the relatively large air pockets, and the irregular nature of the folds, gives the product a crumbly, flaky texture which offers a significantly different mouthfeel when compared to biting into a solid block of chocolate. In addition, the air pockets ensure that the product has a relatively low weight, and hence a low calorific value, when compared to other chocolate bars having a similar bulk.
One method for producing a bar of convoluted chocolate sheet is described in “Chocolate, Cocoa, and Confectionery: Science and Technology”, Third Edition, by Bernard W. Minifie (published in 1989 by Chapman & Hall), on pages 189-190. A kneaded chocolate paste is applied to the first in a series of refining rollers to form a film or sheet of chocolate, which is transferred along the series of rollers. The separation between the rollers controls the thickness of the sheet. At the final roller, a scraper blade removes the sheet from the roller in a plasticised state, causing it to wrinkle and fold into an approximately cylindrical bar. The bar of convoluted chocolate sheet is then transferred by conveyor to a cooling apparatus.
The cross-sectional area of the bar is controlled by the amount of chocolate sheet incorporated into each bar, which in turn is determined by the interval between removing successive bars from the scraper blade (assuming a constant rotation of the rollers). The length of the bars is determined by the length of the rollers and scraper blade; the entire length of the roller/scraper blade (corresponding to the width of the chocolate film on the final roller) may be formed into a single bar of the same length. Alternatively, a series of small sharp protrusions at intervals along the scraper blade may be used to separate the chocolate film into sections as it is removed from the roller, concurrently producing a number of bars of convoluted chocolate sheet, with the lengths thereof determined by the distances between protrusions.
A similar method is disclosed in published International (PCT) Patent Application WO 03/005832 A1.
However, existing bars of convoluted chocolate sheet can be difficult to eat as a result of the crumbly texture. It is difficult to divide the bar into portions, such as for example by taking bites therefrom, or by breaking by hand to share with others, without the bar fragmenting. Such fragmentation can lead to the consumer dropping pieces of chocolate onto the ground or their clothing, and may deter consumers from eating such bars in a public place.
The present invention has been conceived with the above problems in mind.